Average Weather in December in Piñon Hills California, United States
Daily high temperatures decrease by 4°F, from 57°F to 53°F, rarely falling below 43°F or exceeding 66°F. The lowest daily average high temperature is 53°F on December 24.
Daily low temperatures decrease by 3°F, from 35°F to 32°F, rarely falling below 24°F or exceeding 42°F. The lowest daily average low temperature is 32°F on December 26.
For reference, on July 28, the hottest day of the year, temperatures in Piñon Hills typically range from 63°F to 90°F, while on December 26, the coldest day of the year, they range from 32°F to 53°F.
Average High and Low Temperature in December
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in December
The month of December in Piñon Hills experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 37% to 42%. The highest chance of overcast or mostly cloudy conditions is 42% on December 28.
The clearest day of the month is December 1, with clear, mostly clear, or partly cloudy conditions 63% of the time.
For reference, on February 22, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 46%, while on September 7, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 90%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Piñon Hills, the chance of a wet day over the course of December is increasing, starting the month at 10% and ending it at 16%.
For reference, the year's highest daily chance of a wet day is 19% on February 20, and its lowest chance is 0% on June 21.
Over the course of December in Piñon Hills, the chance of a day with only rain increases from 10% to 13%, the chance of a day with mixed snow and rain remains an essentially constant 2% throughout, and the chance of a day with only snow remains an essentially constant 0% throughout.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Piñon Hills is increasing, starting the month at 1.1 inches, when it rarely exceeds 2.5 inches, and ending the month at 1.9 inches, when it rarely exceeds 5.1 inches or falls below 0.1 inches.
Average Monthly Rainfall in December
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. As with rainfall, we consider the liquid-equivalent snowfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day liquid-equivalent snowfall during December in Piñon Hills is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.3 inches or falling below -0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.1 inches on December 19.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Piñon Hills, the length of the day is essentially constant. The shortest day of the month is December 21, with 9 hours, 51 minutes of daylight and the longest day is December 1, with 10 hours, 1 minute of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Piñon Hills is 6:38 AM on December 1 and the latest sunrise is 18 minutes later at 6:56 AM on December 31.
The earliest sunset is 4:40 PM on December 4 and the latest sunset is 10 minutes later at 4:50 PM on December 31.
Daylight saving time is observed in Piñon Hills during 2018, but it neither starts nor ends during December, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:38 AM and sets 14 hours, 28 minutes later, at 8:06 PM, while on December 21, the shortest day of the year, it rises at 6:53 AM and sets 9 hours, 51 minutes later, at 4:44 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
The chance that a given day will be muggy in Piñon Hills is essentially constant during December, remaining around 0% throughout.
For reference, on August 11, the muggiest day of the year, there are muggy conditions 0% of the time, while on September 11, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in December
The average hourly wind speed in Piñon Hills is essentially constant during December, remaining within 0.2 miles per hour of 7.7 miles per hour throughout.
For reference, on April 11, the windiest day of the year, the daily average wind speed is 7.9 miles per hour, while on September 9, the calmest day of the year, the daily average wind speed is 6.0 miles per hour.
The highest daily average wind speed during December is 7.9 miles per hour on December 31.
Average Wind Speed in December
Wind Direction in December
Piñon Hills is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Piñon Hills is gradually decreasing during December, falling by 2°F, from 61°F to 59°F, over the course of the month.
Average Water Temperature in December
The growing season in Piñon Hills typically lasts for 7.5 months (230 days), from around March 29 to around November 14, rarely starting before February 25 or after April 21, and rarely ending before October 26 or after December 6.
The month of December in Piñon Hills is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season decreasing from 16% to 0% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in December
The average accumulated growing degree days in Piñon Hills are essentially constant during December, remaining within 16°F of 3,872°F throughout.
Growing Degree Days in December
The average daily incident shortwave solar energy in Piñon Hills is essentially constant during December, remaining within 0.2 kWh of 3.1 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 3.0 kWh on December 26.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Piñon Hills are 34.433 deg latitude, -117.647 deg longitude, and 4,242 ft elevation.
The topography within 2 miles of Piñon Hills contains very significant variations in elevation, with a maximum elevation change of 1,529 feet and an average elevation above sea level of 4,279 feet. Within 10 miles contains very significant variations in elevation (7,024 feet). Within 50 miles also contains extreme variations in elevation (10,787 feet).
The area within 2 miles of Piñon Hills is covered by shrubs (100%), within 10 miles by shrubs (86%) and trees (12%), and within 50 miles by shrubs (71%) and artificial surfaces (16%).
This report illustrates the typical weather in Piñon Hills year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 6 weather stations near enough to contribute to our estimation of the temperature and dew point in Piñon Hills.
For each station, the records are corrected for the elevation difference between that station and Piñon Hills according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Piñon Hills is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Piñon Hills and a given station.
The stations contributing to this reconstruction are: Southern California Logistics Airport (29%, 29 kilometers, northeast); Ontario International Airport (9%, 41 kilometers, south); Mount Wilson (21%, 45 kilometers, southwest); Palmdale United States Air Force Plant 42 Airport (18%, 46 kilometers, northwest); San Bernardino International Airport (9%, 53 kilometers, southeast); and Edwards Air Force Base (14%, 56 kilometers, north).
Time zones for aiports and weather stations are provided by AskGeo.com .